func installHealthChecker(mux *http.ServeMux) {
// If no health check handler has been installed by this point, add a trivial one.
const healthPath = "/_ah/health"
hreq := &http.Request{
Method: "GET",
URL: &url.URL{
Path: healthPath,
},
}
if _, pat := mux.Handler(hreq); pat != healthPath {
mux.HandleFunc(healthPath, func(w http.ResponseWriter, r *http.Request) {
io.WriteString(w, "ok")
})
}
}